Recently I read posts by @higlander and @6h5c in the big "Marantz CD63 & CD67 mods list" thread.
This got me thinking since I usually remove muting transistors when modding a player. A friend wanted to keep them so I ordered one of the "DPDT Signal Relay Module, 5Vdc, TAKAMISAWA RY5W-K Relay" on eBay to experiment with.
The cd player is a Philips CD614, very nice TDA1543 player capable of way more then what it offers out of the box....
The muting seems typical for many Philips players but gave me some headache while trying to make this relay work. Basically the signal is always high, 8v, so I tried to be smart and connect ground to relay COM and signal to NO, so it would mute just by feeding the mute signal to the relay INPUT. This did not quite work, the relay turned on and off while powering on or off but I could still hear plops.
So I reread the posts and googled and came up with the NOT gate. I managed to construct it from the removed muting circuit parts. I basically reconstructed the muting transistor circuit only adding the NOT gate specific parts, 5v and the output. The output is now the input to the relay and the signal moved from NO to NC and that made it work!
Now when turned on the relay turns on the RCA outputs just a very short time after the player is powered, no more plops... only now a sophisticated relay click!
Wouter
This got me thinking since I usually remove muting transistors when modding a player. A friend wanted to keep them so I ordered one of the "DPDT Signal Relay Module, 5Vdc, TAKAMISAWA RY5W-K Relay" on eBay to experiment with.
The cd player is a Philips CD614, very nice TDA1543 player capable of way more then what it offers out of the box....
The muting seems typical for many Philips players but gave me some headache while trying to make this relay work. Basically the signal is always high, 8v, so I tried to be smart and connect ground to relay COM and signal to NO, so it would mute just by feeding the mute signal to the relay INPUT. This did not quite work, the relay turned on and off while powering on or off but I could still hear plops.
So I reread the posts and googled and came up with the NOT gate. I managed to construct it from the removed muting circuit parts. I basically reconstructed the muting transistor circuit only adding the NOT gate specific parts, 5v and the output. The output is now the input to the relay and the signal moved from NO to NC and that made it work!
Now when turned on the relay turns on the RCA outputs just a very short time after the player is powered, no more plops... only now a sophisticated relay click!
Wouter